JPS59159097A - Coolant degassing device in light water reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coolant degassing device for a light water reactor.

A conventional light water reactor coolant degassing device is shown in Figure 1.2. First, to explain the coolant degassing device shown in Figure 1, (α)
is the cold material extraction line connected to the reactor's primary cooling system (
h) is a volume control tank, ('1) ('2) is a gas compressor, (d) is a hydrogen separator, (ε) is a pressure control device with minimal flow rate, ge) is a gas damping tank, (g) is the filling line, and the secondary coolant (light water) contains water splitting (H) due to radiation.
20→H2, Oz), hydrogen gas is intentionally included in the secondary coolant. The generated radioactive noble gas is contained in the primary coolant and exits the extraction line (α) together with the secondary coolant and hydrogen gas. These hydrogen gas and radioactive noble gas are in trace amounts and are non-condensable. The above-mentioned secondary coolant is led to the volume control tank (b) via the extraction line (α).However, here, by supplying hydrogen gas +A) and purging, radioactivity is removed from the secondary coolant. The rare gas is extracted, and the radioactive rare gas containing hydrogen gas taken out from the gas space of the volume control tank (b) is transferred to a gas compressor (C1).
) to the hydrogen separator, where the hydrogen gas is separated and removed, and returned to the volume control tank th) via the gas compressor (C2). conducting the noble gas via the pressure control device (e) to the gas attenuation tank J) and storing it there, while returning the primary coolant in the volume control tank (b) to the reactor primary cooling system;
- Efforts are being made to reduce the concentration of radioactive rare gases in the secondary coolant and the amount of radioactivity released from the plant.

Next, to explain the coolant degassing device shown in Fig. 2, (a) (
b) (c) (7'l (7) is the same part as above, (d
') is a hydrogen recombination device, in which a primary coolant containing hydrogen gas and a radioactive noble gas is guided through an extraction line (α) to a volume control tank (b), where hydrogen gas (A) is supplied, The radioactive rare gas is extracted from the secondary coolant by -, and the radioactive rare gas including hydrogen gas taken out from the waste space of this volume control tank (h) is passed through the gas compressor (C). Here, oxygen gas (B) is supplied, hydrogen gas is extracted as water (D), and the remaining radioactive rare gas is transferred to a gas attenuation tank (cL').
At the same time, the primary coolant in the volume control tank (b) is returned to the reactor primary cooling system to reduce the concentration of radioactive noble gas in the secondary coolant and the amount of radioactivity released from the plant. ing.

In the light water reactor coolant degassing device shown in Fig. 1.2, the primary coolant extracted from the primary cooling system of the reactor is guided to the volume control tank (h).
Since the radioactive rare gas is extracted by supplying and purging, there is a limit to the effect of reducing the concentration of the radioactive rare gas in the secondary coolant. Also, when the plant is shut down, the primary coolant extracted from the reactor primary coolant system is sent to the volume control tank (b).Meanwhile, nitrogen gas is supplied to the same tank (b) to Since the radioactive rare gas is extracted using the method, there is a problem in that it takes a long time to reduce the concentration of the radioactive rare gas in the secondary coolant.

The present invention addresses the above-mentioned problems and provides a degassing tower for degassing the gas in the coolant received from the primary cooling system of a nuclear reactor using steam from the coolant, and a gas space of the degassing tower. A first condenser that condenses the steam that is introduced into the receiver and returns it to the degassing tower, and a second condenser that condenses the vapor in the gas that is introduced into the receiver by valving an ejector from the first condenser. This invention relates to a coolant degassing device for a light water reactor characterized by having a
The purpose is to efficiently and quickly reduce the concentration of radioactive rare gases in the coolant. (M cost can be reduced.

An object of the present invention is to provide an improved coolant degassing device for a light water reactor that does not require maintenance for a long period of time.

Next, the light water reactor coolant degassing device will be explained with reference to an embodiment shown in FIG. 3. (1) is a coolant extraction line connected to the reactor primary cooling system, (2) is a volume control tank,
(3) is the light heavy line, (3) is the coolant extraction line (
A coolant extraction line branched from 1), (4) a degassing tower, (5) a steam line extending from the gas space of the degassing tower (4), (6) a first condenser, and (7) ) is the gas line extending from the first condenser (6), (8) is the ejector, (
9) is the second condenser, a (1) is the ejector, 01) is the second condenser, (12) is the ejector, 03) is the second condenser, a is the second condenser u , (from 'waste gas system (1
Radioactive noble gas (waste gas) line extending to 51, (lf3
1 is a condensed water line extending from the first condenser (6) to the degassing tower (4), and (L7) is a condensed water line extending from the first condenser (6) to the degassing tower (4).
)'s cooling water, the α information is the second condensed water (9)
(II) Cooling water line of Q31, (l well is a coolant line extending from the degassing tower (4), Fj is a circulation pump, (
2D is the same circulation 1 donz (coolant branched from the discharge side of 20) (27J is the heater, (26) is the same heating pipe C
2 auxiliary steam line (23+ is the steam line extending from the heating pump (n) to the degassing tower (4), (219 is the steam line extending from the discharge side of the circulation pump (20) to the volume control tank (
2), the coolant line (26+) is the coolant line that extends from the coolant line (24) to the coolant extraction line (3), and 06+ is the coolant line (8) (+0
This is a driving steam line that extends to one stroke.

Next, the operation of the coolant degassing device for the light water reactor will be explained.

The primary coolant extracted from the reactor primary cooling system is led to the degassing tower (4) through the coolant extraction line (11 (3)) and is sprayed in the form of a spray. Tower (4
) is led to the heater Cz via the coolant line (one circulation bond Cω coolant line (2)J),
Here it becomes steam and passes through the steam line to the degassing tower (4)
The steam is guided to the coolant extraction line (3).
Gas components are separated and removed from the coolant that is led to the degassing tower (4). In addition, the steam containing gas components present in the gas space of the degassing tower (4) is led to the first condenser (6) via the steam line (5), and is cooled by a cooling water line (1η of cooling water). Most of the steam becomes condensed water and is returned to the degassing tower (4) via the condensed water line μ6). At this time, driving steam is injected from the driving steam line (26) to the ejector (8) (00) θ) on the downstream side of the first condenser (6), and the driving steam There is negative pressure inside. Therefore, the gas component containing steam in the first condenser (6) is sucked into the ejector (8), which is led together with the driving steam to the second condenser (9) to cool the cooling water line 08). Cooled by water, most of the steam becomes condensed water, which is taken out of the second condenser (9). In addition, the gas component containing steam in the second condenser (9) is sucked into the ejector (10), which is led together with the driving steam to the second condenser θ1), where the cooling water in the cooling water line 08) is Most of the steam becomes condensed water, which is taken out of the second condenser 0I.

In addition, the gas component containing steam in the second condenser 01) is sucked into the ejector (121), which is led together with the driving steam to the second condenser 5 (13), where the cooling water line (1 Cooled by cooling water, most of the steam becomes condensed water, which is taken out to the outside of the second condensing Rat 13).

Also the same second condensation? , % (The gas component in 13i is the driving pressure (approximately 0.5
kl? /2G) and sent to the waste gas treatment system.

In addition, the coolant degassed in the degassing tower (4) passes through the circulation pump (20), the coolant C position, and the volume control tank (2).
). However, in order to keep the amount of coolant flowing into the degassing tower (4) constant, some coolant is passed through the coolant line 00.
and is returned to the coolant extraction line (3).

The coolant degassing device for a light water reactor of the present invention, as described above, guides the coolant containing gas components to the degassing tower (4) to separate and remove the gas components in the coolant with steam. is injected to the ejector (8) QO) (12+, which is also ejector (8) 00) (12) and the upstream condenser (6) (9).
Inside Qli (1) Aspirate the gas component containing M'A,
Steam is condensed with the inside of these condensers turned negative and positive to separate and remove the steam in the gas components, making it possible to efficiently and quickly reduce the concentration of radioactive rare gases in the coolant. It has the effect of Furthermore, an ejector with a simple structure is used as the negative pressure generating device, and the installation cost can be reduced compared to the case where a vacuum pump is used. Also, the ejector has
Unlike vacuum pumps, there are no rotating parts, making maintenance unnecessary for a long time. In addition, most of the gas sucked by the negative pressure generator is hydrogen gas, so in the case of a vacuum pump, it is necessary to prevent air from entering, but in the case of an ejector, it is necessary to prevent air from entering. In addition, the driving steam pressure injected into the final stage ejector can be used as the fluid driving pressure to send the separated and removed radioactive rare gas to the waste gas treatment system. This eliminates the need for a blower for transporting radioactive rare gas (waste gas), which also has the effect of reducing equipment costs.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

FIG. 1.2 is a system diagram showing a conventional light water reactor coolant degassing device, and FIG. 6 is a system diagram showing an example of a light water reactor coolant degassing device according to the present invention. (4)--One theory gas tower, (61--1st condenser, (
8! (10)(2)-m-ejector, (9)Ql)(t
3! --First and second condenser. Sub-agents: 12 patent attorneys who are important to Kaimoto

Claims (1)

[Claims] A degassing tower that degass the gas in the coolant received from the reactor primary cooling system by using steam from the coolant, and a degassing tower that condenses the steam received from the gas space of the degassing tower to degas the gas. Cooling of a light water reactor characterized by comprising a first condenser that returns to the tower, and a second condenser that condenses vapor in gas received from the first condenser via an ejector. Material degassing equipment.